Does NAT Network Port Forwarding Not Work in VirtualBox?

NAT Network Port Forwarding Not Working with VirtualBox on Windows Server 2022 RAS

In this article, we will discuss the issue of NAT network port forwarding not working when using VirtualBox on Windows Server 2022 RAS (Routing and Remote Access). This problem can prevent you from accessing services or applications hosted inside the VirtualBox virtual machine from the outside network.

Prerequisites

Before we dive into the solution, let's make sure we have the following prerequisites:

• Windows Server 2022 installed as the host operating system
• VirtualBox installed on the Windows Server 2022 host
• A VirtualBox virtual machine running with a NAT network
• A VPN server (LT2P/IPSec) installed on the Windows Server 2022 host

Issue Description

When setting up a VPN server (LT2P/IPSec) on Windows Server 2022 RAS, and configuring NAT network (172.16.1.0/24), you may encounter an issue where port forwarding rules do not work as expected. In this scenario, you might have tried adding rules with an empty Host IP, but they still do not function correctly.

Possible Solutions

Let's explore some possible solutions to help you get NAT network port forwarding working with VirtualBox on Windows Server 2022 RAS:

Solution 1: Enable NAT Network Port Forwarding on VirtualBox

The first step is to ensure that NAT network port forwarding is enabled on the VirtualBox settings for the virtual machine. In your VirtualBox Manager, select the virtual machine and go to the "Settings" tab. Navigate to the "Network" section and choose the "NAT" adapter. Enable the "Enable NAT network port mapping" option and make sure the "Port forwarding" tab is enabled as well.

Solution 2: Configure RAS to Use Static NAT

Another solution is to configure RAS to use Static NAT instead of the default DHCP server. This will ensure that the VirtualBox virtual machine always receives the same IP address, making it easier to set up port forwarding rules. To do this, go to the "RAS Server" tab in the "Server Manager," select the RAS server, and click on "Properties." Navigate to the "IP Addresses" tab and configure the static IP address for the virtual machine.

Solution 3: Configure Port Forwarding Rules Correctly

Make sure that you have configured the port forwarding rules correctly. When setting up the rules, use the static IP address of the VirtualBox virtual machine instead of the empty Host IP. Also, ensure that the protocol and port number are specified correctly.

Code Example

Here's an example of a correctly configured port forwarding rule:

Interface: LAN
 Name: VPN
 IP Address: 192.168.1.10
 Subnet Mask: 255.255.255.0
 Enabled: Yes
 Security:
  - Inbound:
    - Protocol: TCP
    - Local Port: 80
    - Remote Port: 80
    - Remote Address: Any
    - Description: HTTP

In summary, when dealing with NAT network port forwarding not working with VirtualBox on Windows Server 2022 RAS, you can try enabling NAT network port mapping on VirtualBox, configuring RAS to use static NAT, and setting up port forwarding rules correctly using the static IP address of the VirtualBox virtual machine.

References

• Microsoft Docs: RAS Server Port Forwarding
• VirtualBox Manual: NAT Networking